Right-hand rule

The three-finger rule, even UVW rule, IBF or FBI usually called, is a rule of thumb for illustrative determination of the orientation of three mathematically or physically contiguous vectors of a three-dimensional coordinate system, usually of a right or legal system, which is why this rule is often is also referred to as a right-hand rule. However, the latter is also a synonym for the rights Fist or corkscrew rule.

It should be noted that three-finger rules under reflection of the coordinate system (i.e. sign reversal of all three coordinate axes ) maintain their validity, and therefore to any "right- hand rule " complementary "left -hand rule " (see can be formulated and ), in which two of the three vectors retain their orientation.

Geometry

The orientation of the vector which results from the cross product of the three-dimensional space is illustrated by the right hand thumb points in the direction of the vector, the index finger in the direction of the vector. Thumb and forefinger lie in a plane with the palm. The middle finger is from 90 ° and points in the direction of the resultant of the vector product vector (see picture above).

This can also be used for the orientation of the orthogonal coordinate system.

Electrical Engineering

Procedure for determining the deflection of a current- carrying conductor in a magnetic field Duch:

For the Lorentz force applies:

(: Charge of the particles, on which the force acts, wherein electrons) or

(: Current-carrying conductor piece )

The thumb points in the direction of the cause, for example, in the direction of current or the direction of movement of the positive charge (and hence counter to the direction of movement of the electrons).

The index finger points vertically to the thumb parallel to the magnetic field lines, so the mediation (including link ), the magnetic field.

The middle finger is perpendicular to the thumb and index finger in the direction of the effect of the Lorentz force.

On the other hand also cause the relative movement of the conductor in the magnetic field. The effect in this case, the forced movement of the electrons along the conductor, called electromagnetic induction of an electric current.

Hence the name UVW or FBI usually originates ( Note the different order of the fingers, see picture above).

To determine the direction of the magnetic field of a current-carrying coil see the rights - fist rule.

There is also the right foot to the direction of motion of the electrons "left -hand rule " or "left - thumb - rule". As the following figure shows, these rules no longer function analogous to the rules of the right hand, but on the basis conventional or " technical " direction, but the movement of the electrons, which then is particularly useful when analyzing the motion of negatively charged particles, such as the conduction electrons, cathode rays, etc., since in this case a conceptual reversal of the direction of the charge carrier movement and calculation may waive the negation ( the charge in the Lorentz formula, see above). Due to the traditional dominance of the right-hand rules, however, many people find the left -hand rule as an additional rule that confuses more than support, even more so than is handled well in the classroom very inconsistent with their placement.

Rule of thumb

In addition to the " UVW " are two other rules to remember.